After developing a highly sensitive and robust sandwich ETA for inducible nitric oxide synthase (iNOS), we discovered this protein free in plasma of patients with systemic inflammatory response syndrome (SIRS) or sepsis, but could not detect it in plasma obtained from healthy individuals. Our novel discovery has lead us to proposed that the increased plasma level of iNOS can serve as a valid biochemical marker to prognosticate the onset of SIRS and/or sepsis and to monitor a patient's condition as it improves or deteriorates. Our goal is to develop an innovative new clinical diagnostic that can rapidly detect, quantitate and monitor this increase in iNOS prior to the onset of severe sepsis and septic shock, and thus provide an early warning signal for future deleterious events. An early diagnosis will provide a basis for the earlier initiation of therapies than is currently practiced. The results from two prior studies indicate that an increased plasma level of iNOS can be detected and measured in patients with SIRS and/or sepsis, occurs early in an episode of SIRS and/or sepsis, and forecasts future problems. The aims of this phase 2 project are (1) to extend the study to 400 patients in order to assess if the observations made on two smaller cohorts of patients are generally applicable and (2) to determine if the increased plasma level of iNOS in SIRS and sepsis is unique to this pathology and does not occur in other diseases associated with an over expression of iNOS. Once completed, this project will bring a unique and much needed new clinical diagnostic onto the market, and this, in turn, will lead to improved health care for critically ill patients. PROPOSED COMMERCIAL APPLICATIONS: Over 1,200,000 cases/yr of systemic inflammatory response syndrome and sepsis occur in the USA; these lead to over 500,000 cases/yr of severe sepsis and septic shock and 100,000 - 250,000 deaths/yr. A rapid test to assess a patient's entry into and progress down the sepsis pathway to severe sepsis and septic shock is needed. Our EIA is designed to meet this clinical need, to lower patient cost by reducing the length of ICU stays. and to improve patient outcome.